Field of Invention
The present invention relates to motor control technology. More particularly, the present invention relates to a motor control system and a method thereof.
Description of Related Art
Motors have a wide range of uses in our daily lives. For instance, the fan utilized in motherboards, computer casings and projectors, etc. for improving heat dissipation is usually driven by motors. Motors are also often seen in small home appliances such as blenders and in various toys such as robots.
In various motor applications, the technique of pulse width modulation (PWM) is used to adjust the magnitude in the current of a motor in order to save power and control the speed of the motor. The technique of PWM involves adjusting a ratio of a power-transmitting time and a non-transmitting time within a period of a square wave, in which a power supply transmits power to a load in the power-transmitting time. The proportion of the power-transmitting time with respect to the length of the square wave is also known as duty cycle. However, a conventional control unit that controls the speed of the motor usually identifies certain forms of high/low levels only. If a PWM unit for generating the square wave generates the forms of high/low level that the control unit cannot recognize due to process variations or other design factors, the control unit cannot control the motor in an appropriate manner.
Therefore, what is needed is a new motor control system and a control method thereof for addressing the issues mentioned above.